I think both careers, Architecture and Urban Planning involve a list of socio-cultural factors, and it is very important to take into account aspects as climate, environment and context! I think Architecture and Urban Planning are not so different. The scale that they work with is not the same, but the principles are! And also the client, because urban planners work for a community and architects do for a single client or a small group of clients. Maybe Urban Planning is the art of making places, as Teresa Almeida d'Eça said, whereas Architecture is the art of making spaces!